Effect of Mo in V-microalloyed Precipitating-strengthen High Strength Steel

The effects of Mo element on the precipitation of low temperature bainite zone in V microalloyed steels were investigated for the V microalloyed steels,by means of isothermal precipitation simulations,TEM,calculation of Thermo-calc software.And the effect of Mo element on the mechanical properties of V microalloyed steel was investigated by hot rolling experiment and mechanical properties test in laboratory.The results show that the addition of Mo can significantly improve the precipitation potential.When the Mo content increases from 0% to 0.6%,the volume fraction of precipitates can be increased from 0.019% to 0.025% for the sample held at 600℃ for 40 min.The addition of Mo element can significantly improve the strength of the V microalloyed steel.The yield strength and tensile strength of the steel with 0.6% Mo element are 667 MPa and 803 MPa,respectively, which are 113 MPa and 119 MPa more than these of the steel without Mo addition.